The present invention refers to a flexible liner for shipping bulk load inside shipping containers which is basically constituted of a flexible liner that is configured in the form of a sack or bag, and which is intended to be placed inside a plurality of means of transport for bulk load, such as towers, trucks, rail wagons or containers for load storage by air or sea, as well as a method for placing said flexible liner inside a space or container for bulk load storage.
As we know, presently, the transport of bulk load, whose materials may include substances in the form of powders, balls, flakes or granules, also including grains, liquids and others, is usually made in containers, whose dimensions meet the international specifications, and which may be transported fitted on land based vehicles, and these said containers will further be able to, for economic reasons, be stacked, one on another, to allow its transport on board of ship or aircraft.
Many types of flexible liners already known from the state of the art are placed inside containers, which usually present a rectangular configuration, and kept suspended inside the container through means of support that are attached into eyelets disposed in the superior part of the internal side walls of the container; however, it was found that most of these flexible liners presents the inconvenience of having their fastenings loosened from the eyelet, and even their tearing, in function of the conditions they are submitted during transport of the container, due to the movement of the load inside the flexible liner, it may allow the bulk load to spill from the liner into the container, causing therefore its loss and/or contamination of whole load, and, consequently, contaminating the container itself, and, in more extreme cases, besides it may cause serious accidents involving the personnel responsible for the discharge of the load; however, the most serious inconvenience observed on the usage of flexible liners known from the state of the art is the fact that, when the load is fed into the flexible liner for its shipment, or when the door of the container is opened for inspection of the load already loaded inside the flexible liner, part of the back wall of the flexible liner which becomes exposed suffers an arching outward, in function of the internal pressure that it is submitted by the load against the internal surface of said part of the back wall of the flexible liner, this fact may cause a great difficulty, or even disable to close the door of the container again.
Aiming to overcome the inconveniences previously mentioned, several types of flexible liners were developed to be used inside containers, which reflect the current state of the art, and that will be commented below.
The patent document BR 9.202.694, published in Mar. 23, 1993, by Carlos J. D. Matias, illustrates a flexible liner, that is placed inside a container, being that in part of the back wall of the flexible liner are disposed horizontal and vertical bars, and in the intercessions of which will be fixed oblique strips, whose inferior frontal ends will be fixed on the base of the container, and, when loading the flexible liner, these said oblique strips will be pressured, in order to retain said part of the back wall of the flexible liner, objecting to try to prevent said part of back wall from arching, that tends to occur in function of the pressure that it is submitted by the load against the internal surface of said part of the back wall of the flexible liner.
The patent documents U.S. Pat. No. 3,696,952, published in Oct. 10, 1972, and U.S. Pat. No. 3,868,042, published in Feb. 25, 1975, both in name of Sea-Land Service, Inc., illustrate a flexible sack or bag, that is fastened on the internal walls of the container, being that part of back wall of the flexible liner is reinforced along the loading process, through a plate, in order to avoid it from arching outward, and said part of back wall of the liner is further provided with openings, which are conveniently disposed, such as to allow the loading and the discharge of said flexible liner; said openings will be properly sealed during transport of the container.
The patent document U.S. Pat. No. 3,951,284, published in Apr. 20, 1976, by Du Pont Canada, Ltd., illustrates a flexible liner which employs bars disposed on the inferior part of the back wall of the flexible liner, in order to avoid it from arching outward along its loading, and said part of back wall of the flexible liner is also provided with openings, which are conveniently disposed, to allow the loading and discharge of the flexible liner, and these openings will also be properly sealed during transport of the container.
The patent documents U.S. Pat. No. 3,980,196, published in Sep. 14, 1976, and U.S. Pat. No. 4,054,226, published in Oct. 18, 1977, both in name of United States Lines, Inc., illustrate a back frame, which configures a back plate, that will retain the flexible liner inside the container, in order to avoid part of back wall of the flexible liner from arching outward, and prevent the flexible liner from tear.
The patent document U.S. Pat. No. 4,232,803, published in Nov. 11, 1980, by A.I.R. Foundation, illustrates a pair of retainer elements disposed in angle, to support part of back wall of the flexible liner inside the container, and its construction demands a container comprising a double door obligatorily.
The patent document U.S. Pat. No. 4,601,405, published in Jul. 22, 1986, by The Boeing Company, illustrates a device for closing the part of back wall of the flexible liner, provided that said wall part is formed by three triangular plates, whose free vertices are joined by means of strips that will be attached by means of said closing device.
The patent documents EP 280.493 and EP 280.495, both published in Aug. 31, 1988, U.S. Pat. No. 4,792,239, published in Dec. 20, 1988, U.S. Pat. No. 4,801,042, published in Jan. 31, 1898, all in name of Kawasaki Kisen Kaisha, illustrate adjustable strips, which are employed to retain the flexible liner from the internal walls of the container.
The patent document U.S. Pat. No. 4,875,596, published in Oct. 24, 1989, by Jxc3xcrgen Lohse, illustrates a tubular flexible flask that is supported inside a container, disposed separated from the walls of said container, being that the ends of said tubular flexible flask are joined by means of staple connections.
The patent document U.S. Pat. No. 5,040,693, published in Aug. 20, 1991, by Victor T. Podd and others, illustrates a flexible liner whose back wall is provided with a plurality of horizontal and vertical bars responsible for retaining said part of back wall, in order to avoid it from arching.
The patent document GB 2.226.300, published in Jun. 27, 1990, by Nipon Yusen Kaisha, illustrates a flexible liner that is placed inside a container, and rigid elements are disposed in part of back wall of said flexible liner, in order to avoid said part of the back wall of the flexible liner from arching.
The patent document GB 2.228.468, published in Aug. 29, 1990, by A.P.S. Co. Ltd., illustrates a flexible liner that is placed inside a container, and horizontal bars are disposed in part of back wall of the flexible liner, in order to avoid said part of back wall of the flexible liner from arching.
The patent document FR 2.461.661, published in Feb. 6, 1981, by Pneumatiques, Caoutchouc Manufacture et Plastiques Kleber-Colombes, illustrates a flexible liner, where part of back wall is retained by means of the employment of strips, disposed forming an xe2x80x9cXxe2x80x9d, which are fastened on the side walls of the container.
The patent document EP 21.814, published in Jan. 7, 1981, in name of In Bord Bainne Co-Operative Limited, illustrates a flexible liner that is placed inside a container, and where part of back wall is retained by means of the employment of rigid panels.
The patent document EP 260.652, published in Mar. 23, 1988, by Kawasaki Kisen Kaisha, Ltd., illustrates a flexible liner that is placed inside a container, and horizontal bars are disposed on part of the back wall of the flexible liner, in order to avoid said part of back wall of the flexible liner from arching.
The patent document EP 480.741, published in Apr. 15, 1992, by BJK Industries, Inc., illustrates a flexible liner that is placed inside a container, and horizontal tubular elements are disposed on part of the back wall of the flexible liner, in order to avoid said part of back wall of the flexible liner from arching.
The patent document EP 716.988, published in Jun. 19, 1996, by Caretex A/S, illustrates a flexible liner that is placed inside a container, and a grid element are disposed on part of the back wall of the flexible liner, in order to avoid said part of back wall of the flexible liner from arching.
The patent document EP 982.239, published in Mar. 1, 2000, by Caretex A/S, illustrates a flexible liner that is placed inside a container, and horizontal bars are disposed on part of the back wall of the flexible liner, in order to avoid said part of back wall of the flexible liner from arching.
The patent document EP 1.101.712, published in May 23, 2001, by Caretex A/S, illustrates a flexible liner that is placed inside a container, and reinforcement elements in form of brackets are disposed on part of the back wall of the flexible liner, being that the superior vertices of said bracket elements comprise strips which are fastened one each other, and which are disposed on the middle of the part of the back wall of said flexible liner, in order to avoid it from arching.
In practice, it is observed that all types of flexible liners already known from the state of the art present constructive and/or functional inconveniences, because, in some cases, these flexible liners are provided with an extremely complex construction, what leads to an excessive waste of raw material, a production process involving a high number of stages, and, in other cases, unusual elements are used for the constructive conception of the flexible liner, such as bars, panels, tubular elements or others, which will become one more complicating element in the moment of the discharge from the flexible liner, and in some cases the fastening of the retainer elements that act against the tendency of arching of part of back wall of the flexible liner must be done by means of the employment of muscular force, this necessity does not present enough reliability for the stability of the fastening of the said elements of retention of part of back wall of the flexible liner, since these fastenings, in function of the pressure submitted by the load inside the flexible liner, and due to the movement of the load inside the flexible liner during the transport of the container, may loosen, causing consequently, the detachment of these elements of retention of part of the back wall of the flexible liner, allowing therefore the arching of said part of back wall of the flexible liner, after open the door of the container, preventing it to close again, still occurring critical cases in that the flexible liner tears, causing loss and/or contamination of the load and the container itself.
Aiming to overcome the current inconveniences of the current techniques, a flexible liner for shipping bulk load inside shipping containers and a method for placing said flexible liner for shipping bulk load into a shipping container was designed, comprising basically a flexible sack or bag, made of impermeable plastic material, preferably of impermeable propylene plastic, which is sized to be placed in standard containers, and that will be able to provide the safe transport of bulk loads. It uses fastening means that will keep suspended the flexible liner starting from the superior part of the container, and said container having an optional wall as roof, a floor wall, left and right side walls, a closed front wall and a back wall that may comprise an or more doors, while the flexible liner to be placed inside said container also comprises part of the optional roof wall, part of floor wall, parts of left and right side walls, part of closed front wall and part of back wall, through which the loading of said flexible liner may be performed, and said flexible liner of this invention is characterized by the fact of using means of retention of said part of the back wall of the flexible liner, using frontal transversal retention strips, which are diagonally disposed forming a xe2x80x9cXxe2x80x9d on the external surface of said part of back wall of the flexible liner, and said frontal transversal retention strips of part of the back wall of the flexible liner will be pressured, aided by a tensioning device, in order to be kept stable, what will be reached by using double buckles, being further intended another vertical fastening strip, which extends centrally from the inferior border of part of the back wall of the flexible liner, and which extends up to a middle height of said part of the back wall of the flexible liner, and said vertical fastening strip will be responsible for keeping the intercession point positioned among these said frontal transversal strips of retention of part of back wall of the flexible liner, and so said frontal transversal strips of retention, as said vertical fastening strip, disposed in the part of the back wall of the flexible liner are made of high traction resistance materials, in order to guarantee a perfect stabilization of said part of the back wall of said flexible liner, reducing substantially the tendency of arching of said part of the back wall of said flexible liner, which occurs in function of the internal pressure that is submitted by the loading of the flexible liner, and, due to the fact that the fastening of said part of the back wall of the flexible liner be performed using a tensioning device, it will be possible to guarantee a great reliability on the retention of said part of the back wall of the flexible liner, with minimum effort from the operator.